The present invention relates to expansion plug devices and more particularly to expansion plugs having deformable sealing members.
Plugs for sealing containers are well known and are available in a plethora of shapes, sizes and functional designs. Examples of such plugs are plumbers plugs for stopping pipe-line leaks, barrel bungs, core-hole closing devices and quick-acting stoppers.
In the interest of economy and efficiency, plugs should be adaptable to a variety of conditions and opening sizes. Thus, most of the known plugs have some degree of size variability. One plug having size variability uses a flexible, resilient seal with some type of expander core fitted therethrough. Examples of this design are found in Hearne U.S. Pat. No. 3,550,636, Meulendyk et al. U.S. Pat. No. 3,525,365 and Rice U.S. Pat. No. 2,321,515.
Ease of installation is also a desirable feature for closure plugs. Obviously, an easy installation technique results in a fast and efficient plug installation. Such efficiency results in savings of both manpower and equipment downtime.
A further requirement, perhaps even more important than efficient installation, is stability and reliability of an installed plug. It is obviously undesirable to have a plug fail or come out of place shortly after installation.
The drawbacks inherent with presently known plugs are magnified when such plugs are to be installed under difficult environmental conditions such as are found in underwater applications. Installation of presently known plugs usually requires tools (e.g. wrenches, screwdrivers and the like). Such tools must be carried by a diver to the container. Any additional equipment which must be carried by a diver is cumbersome and unwieldy. Furthermore, in underseas applications, environmental pressures reach extreme levels thus causing high levels of strain on any plug used. High environmental pressures tend to exaggerate the drawbacks of tapered plug expanders such as the device shown in Meulendyk. High pressures cause migration or movement of any flexible sealing member along the expander core. Such migration may eventually lead to failure of the plug by movement of the sealing member out of the opening. Thus, while some presently available plugs ameliorate some of the above-discussed drawbacks, none of the presently-known plugs ameliorate all of these drawbacks.
The present invention overcomes these drawbacks by providing a flexible, readily insertable and removable plug having a core expander member shaped to prevent sealing member migration once the plug is installed.